2 Reproductive-BIO 102 HANDOUTThe testes are located outside of the body because sperm need lower temperatures to survive.Sperm production takes place in the seminiferous tubules of the testesIn between the seminiferous tubules are interstitial cells which produce testosterone, the male hormone.Many seminiferous tubules join to become the epididymus which is located at the rear of the testes. Sperm are stored here and maturation also occurs.Reproductive-BIO 102 HANDOUT

3 Reproductive-BIO 102 HANDOUTSperm enter the vas deferens or ductus deferens (the sperm duct) which passes through an opening in the wall of the body called the inguinal canal.The ability of newly formed sperm to swim develops in the epididymis and the vas deferens.Sperm continue their maturation here.A vasectomy ties off the vas deferens so sperm are no longer available for fertilization.Reproductive-BIO 102 HANDOUT

4 Reproductive-BIO 102 HANDOUTThe vas deferens connects to the ejaculatory duct after it merges with the seminal vesicle duct.When the male ejaculates semen, rhythmic contractions of smooth muscle propel the sperm through the ejaculatory duct and then through the urethra.The penis is the male organ of sexual intercourse. It contains erectile tissue that fills with blood and causes the erection during sexual stimulation.Reproductive-BIO 102 HANDOUT

5 Reproductive-BIO 102 HANDOUTGlands which help sperm survive:Seminal vesicles produce seminal fluid which is a watery mixture containing fructose, which provides energy for the sperm, and prostaglandins which are thought to induce muscle contractions in the female reproductive system that help sperm travel more effectively.Prostate gland: surrounds the urethra and produces an alkaline fluid which is added to the seminal fluid. This raises the pH of the vagina to a more optimal pH for sperm survival.Typical size of prostate gland is about that of a kiwi fruitCowper’s or bulbourethral glands secrete mucus into the urethra during sexual arousal. This provides lubrication for intercourse and washes away traces of acidic urine before the sperm arrive.Reproductive-BIO 102 HANDOUT

6 Reproductive-BIO 102 HANDOUTMeiosis:Purpose: produces sperm and eggs with half the number of chromosomes (23) of somatic cells. (Cells with ½ the chromosomes are called haploid cells.)Sperm formation and maturation takes about 9-10 weeks. Sertoli cells surround and nourish the growing sperm cells.Egg maturation and release takes about 14 days and occurs once per monthReproductive-BIO 102 HANDOUT

7 Reproductive-BIO 102 HANDOUTCell division terminology:Gamete: sperm or egg produced by meiosisDiploid: describes the “normal” number of chromosomes in any cellHaploid: cell which contain 23 chromosomes (1/2 the “normal” amount)Reproductive-BIO 102 HANDOUT

8 Reproductive-BIO 102 HANDOUTSpermconsist of 3 major parts: a head, midpiece, and a tail.The head contains the nucleus and 1/2 of the chromosome number of the parent.Acrosome covers the head. This is a cap containing enzymes that help the sperm penetrate the eggThe midpiece contains mitochondria and ATP. These produce the energy to power the tail.The tail propels the sperm.Reproductive-BIO 102 HANDOUT

11 Reproductive-BIO 102 HANDOUTThe Labia Minora are 2 smaller, highly vascular, hair free folds.The Clitoris is a small organ partly enclosed by the labia minora. It is composed of erectile tissue and is highly sensitive.The Urethral opening lies between the clitoris and the vaginal opening.Reproductive-BIO 102 HANDOUT

12 Reproductive-BIO 102 HANDOUTInternal female reproductive organsOvaries are the primary reproductive organs. They lie near the ends of the fallopian tubes (also called oviducts) in the upper pelvic cavity. They are held in place by several ligaments. Ovaries differentiate from tissues which will become the abdominal wall early in fetal development.The ovaries produce eggs called oocytes at regular intervals during the reproductive years. Eggs have 1/2 the number of chromosomes as the parent.Reproductive-BIO 102 HANDOUT

13 Reproductive-BIO 102 HANDOUTThey also produce the hormones estrogen and progesteroneThe distal ends of the fallopian tubes are funnel shaped and have fingerlike projections called fimbriae. These create waves or currents which sweep the egg from the ovary into the pelvic cavity into the fallopian tube. They do not touch the ovary itself.The egg is propelled toward the uterus by the cilia on the walls of the fallopian tubes.If fertilization by a sperm occurs, it usually takes place in the distal third of the fallopian tube. Eggs take about 3-4 to 7-10 days to reach the uterus.Reproductive-BIO 102 HANDOUT

14 Reproductive-BIO 102 HANDOUTThe uterus is a hollow, pear shaped, muscular organ which is located between the bladder and the rectum. It will “incubate” the fertilized egg.Its narrow, lower end is called the cervix. The middle part of the uterus is called the body and the upper part is called the fundus.Reproductive-BIO 102 HANDOUT

15 Reproductive-BIO 102 HANDOUTUterine layersEndometrium: inner layer; lining of epithelial tissue, glands, connective tissue and blood vesselsThis is the layer that sloughs off during menstrual flow.A fertilized egg will implant into this layer. After implantation, the endometrium helps form the placenta which provides nourishment, waste removal, and gas exchange to the fetus.Reproductive-BIO 102 HANDOUT

17 Reproductive-BIO 102 HANDOUTThe Breasts are considered to be part of the reproductive organsare really modified sweat glands which produce milk to nourish newborn infants.milk production (lactation) is stimulated by estrogen and progesterone only when birth has actually occurred.the nipple is at the center of each breast. It contains smooth muscles that can contract and cause the nipple to become erect.Reproductive-BIO 102 HANDOUT

18 Reproductive-BIO 102 HANDOUTSurrounding the nipple is the pigmented areola.Internally, the breasts contain mammary glands that produce milk.The glands consist of many milk producing lobules. Contractile cells around each lobule allow the milk to be released and ducts deliver the milk to the nipple.Most of the breast consists of adipose tissue so breast size doesn’t indicate the potential for milk production.Reproductive-BIO 102 HANDOUT

19 Reproductive-BIO 102 HANDOUTMenstrual CycleEach month the ovaries and uterus go through a pattern of changes called the menstrual cycle.Typically lasts 28 days; is controlled by hormonesMenstrual cycles begin at puberty and end at menopauseA complete menstrual cycle consists of 2 linked cycles (they both must occur): an ovarian and a uterine cycleOvarian cycle (condensed): oocytes mature and are releasedImmature follicle develops; GnRH, FSH and LH increaseReproductive-BIO 102 HANDOUT

20 Reproductive-BIO 102 HANDOUTEstrogen and progesterone secretedFollicle matures; now called Graafian follicleIncreasing estrogen causes surge of LH so that ovulation occurs—the egg is released (typically at the middle of the cycle) and swept toward the fallopian tubeA corpus luteum forms from the ruptured follicle site and secretes large amounts of estrogen and progesterone to prepare the endometrium for the possible pregnancyIf no pregnancy occurs, estrogen and progesterone levels decline and another menstrual cycle begins.Reproductive-BIO 102 HANDOUT

21 Reproductive-BIO 102 HANDOUTIf the egg is fertilized, it moves down the fallopian tube and implants in the uterine endometriumThe developing embryo secretes its own hormones to enable the corpus luteum to continue to secrete estrogen and progesterone until the placenta develops.The placenta will take over the job of secreting progesterone and estrogen as well as become a nutrient/waste filter between the maternal and fetal circulation.Reproductive-BIO 102 HANDOUT

24 Polycystic ovary syndrome (PCOS)common hormonal disorder among women of reproductive age.The name of the condition comes from the appearance of the enlarged ovaries containing numerous small cysts in most, but not all, women with the disorderOvaries produce excessive amounts of male androgensSigns and symptoms vary:Menstrual abnormality.Excess androgen. Elevated levels of male hormones (androgens) may result in excess facial and body hair (hirsutism), adult acne or severe adolescent acne, and male-pattern baldnessPolycystic ovaries. Enlarged ovaries containing numerous small cystsReproductive-BIO 102 HANDOUT

25 Reproductive-BIO 102 HANDOUTCausesExact cause unknown; these factors thought to play a role:Excess insulin.Low-grade inflammation.Heredity. If your mother or sister has PCOS, you might have a greater chance of having it, too.Abnormal fetal development. excessive exposure to male hormones (androgens) in fetal life may prevent genes from working the way they're supposed to.No specific test to definitively diagnose; diagnosis is made by exclusion, rule out other possible disorders.Reproductive-BIO 102 HANDOUT

26 Reproductive-BIO 102 HANDOUTTreatment:treatment focuses on management of individual concerns, such as infertility, hirsutism, acne or obesity.Regulate the menstrual cyclelow-dose birth control pills that contain a combination of synthetic estrogen and progesterone.an oral medication for type 2 diabetes that lowers insulin levels. This drug improves ovulation and leads to regular menstrual cycles.also slows the progression to type 2 diabetes if you already have prediabetes and aids in weight loss if you also follow a diet and an exercise program.Reproductive-BIO 102 HANDOUT

27 Reproductive-BIO 102 HANDOUTHelp you ovulate. If trying to become pregnant, you may need medication to help you ovulate.Reduce excessive hair growth: birth control pills to decrease androgen production or medication that blocks the effects of androgens on the skin.Surgery If medications don't help you become pregnant, an outpatient surgery called laparoscopic ovarian drilling is an option for some women with PCOS.part of the ovaries are destroyed to try to restore regular ovulation cyclesReproductive-BIO 102 HANDOUT

28 Infertility: Inability to ConceiveMany causes of infertility:Number and quality of sperm, pelvic inflammatory disease (PID), endometriosisEnhancing fertility:Options: artificial insemination, in vitro fertilization, GIFT (Gamete intrafallopian transfer- no in vitro procedures used; harvested eggs are mixed with sperm are transferred into the fallopian tube to hopefully fertilize an egg and implant in the uterus) andZIFT (Zygote intrafallopian transfer—oocytes fertilized in vitro are immediately transferred to the fallopian tube with the hopes the zygote will implant),fertility-enhancing drugs, surrogate mothersReproductive-BIO 102 HANDOUT

30 Reproductive-BIO 102 HANDOUTSyphillis Most people don’t notice early symptoms. Without treatment, it can lead to paralysis, blindness and death. Can be cured with antibioticsSigns: First sign is usually a firm, round, painless sore on the genitals or anus.The disease spreads through direct contact with the sore.Later, may see a rash on the soles, palms, or other parts of the body as well as swollen glands, fever, hair loss or fatigue. In late stages, symptoms come from damage to organs such as the heart, brain, liver, nerves and eyes.Reproductive-BIO 102 HANDOUT

31 Reproductive-BIO 102 HANDOUTGonorrhea spreads easily and can lead to infertility. Antibiotics stop the infectionSymptoms: burning during urination and discharge. In men, may see penile discharge, swollen testiclesIn women: vaginal discharge, pelvic pain, spotting. Symptoms may be confused with a urinary tract or vaginal infection Late in the infection, may see skin rashes or spread of the bacteria to the joints and blood.Reproductive-BIO 102 HANDOUT